I want to discuss two moral aspects of how to talk about
borderline people (e.g., whether to say “MTF” or “female”, “smart”
or “good at math”).

The first aspect is what category of people we should be talking
about, never mind how we talk about it. Usually, for a given
category C, there are many ways to be borderline C: people can
be

borderline female due to a lack of chromosomes or a lack of
genitals;

borderline smart because they keep exchanging quantifiers or
because they keep estranging family;

borderline safe because they drive over the speed limit or roll
their bike past a stop sign;

borderline documented because they burned their passport,
overstayed their visa, or came from an unrecognized “country”.

Of course, it is easy enough to construct a category C’ that
firmly includes or excludes particular kinds of borderline Cs
(e.g., you are female’ iff you have XX chromosomes), if only to
leave unresolved lower-dimensional borderlines (e.g., what if only
half of your cells have XX chromosomes). So let’s ask not what
categories exist (because they all do) but what categories we
should talk about.

It might well be that we should talk about different versions of
C for different purposes (e.g., medicine, sports, identification,
love). It might also be that delineating categories at their edges
is not usually worth our collective cognitive trouble. Regardless,
sometimes in conversation or other collaboration I find that
multiple versions are actually relevant. For example, some people
wonder whether to call a transgender person “male” or “female”, and
I think a transgender person can firmly belong to a gender
category that we should talk about. Unfortunately, when I tried to
work with others to distinguish and choose among versions of
categories, I have often been frustrated.

When people in power to classify others don’t take the effort to
apply the right category version, the misclassified people can get
slighted. I empathize with the misclassified people because I have
been misclassified—for example, I don’t need a passport to travel
internationally, and I am a computer scientist.

The second aspect is how to name a given category (version).
Even in a context where we agree intellectually that there is
exactly one gender category we should talk about (say “female”) and
a transgender person belongs to it firmly, the term “female” still
takes many people today more thought to produce and comprehend when
applied to a person known to be transgender than when applied to a
person known to be cisgender. So, it is tempting for a well-meaning
speaker to avoid gender categories altogether by terming a
transgender person “female-presenting” instead. The
“female-presenting” characterization

is certainly true,

but may be a cop-out because it

perpetuates the implicature that the person doesn’t quite
belong

and increases their work to counter misclassification,

yet may be justifiable (perhaps in some strain of
utilitarianism), though a justification remains to be spelled out
and applied uniformly to all instances.